STUDIES ON THE ACCELERATING EFFECT OF THIAMINE AND ITS DERIVATIVES ON YEAST FERMENTATION

Abstract

The bakers' yeast fermenting with the maximum rate under suitable conditions shows still more carbon dioxide production provided that a minute amount of thiamine is added. This phenomenon was discovered by Atkin, Schultz, and Frey, and was applied for microdetermination of this vitamin. By use of this determination method, the authors examined the accelerating effect of thiamine and twenty-three kinds of its derivatives on anaerobic carbon dioxide production, and found that this method could be used as an examination method for the biological activity of thiamine analogues. However, care must be taken of the fact that the effect on yeast do not always agree with the effect on animals. Among the thiamine analogues tested, 1) Analogues of S, S-alkyl type were found to be nearly as active as thiamine, and some of them were slightly more active than thiamine. 2) When the analogues of O, S-diacyl type were examined, the effect of O, S-diacetyl thiamine was found to be almost the same as that of thiamine. Among the following compounds, the full developement of the effect was delayed in case of the later-cited compound compared with the former-cited. O, S-diacetyl>;dipropionyl>;propionyl-benzoyl>;dibenzoyl However, after the full developement of the accelerating effect, all of these analogues were as effective as thiamine. 3) O-acyl analogues were slightly less effective than thiamine. 4) S-alkyl analogues were not effective in general. 5) Thiothiamine and its derivatives did not show any activity. 6) Three kinds of antivitamins were tested, but among these only oxythiamine exhibited a slight anti-thiamine activity. As to the mechanism of the acceleration, it was assumed that the nitrogen metabolism had an essential interrelationship with the effect. It was observed that the nitrogen source was indispensable for the development of the effect, and the increase in nitrogen content and sporation rate of yeast cells accompanied with the increase of the effect. Metal ions and the cell-membrane permeability also played some role for the development of the accelerating effect.